#game-container {
    width: 800px;
    height: 600px;
    border: 1px solid black;
    position: relative;
    background-color: #008000;
}

#tank {
    width: 50px;
    height: 50px;
    background-color: #FF0000;
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
}

.bullet {
    width: 5px;
    height: 10px;
    background-color: #FFFF00;
    position: absolute;
}